John e



J. HILBISH.

UNWERSAI. CORD C|RCU|TS- APPLICATION FILED JAN. 30.

Patented Aug. 22, 1922.

UNITED STATES PATENT OFFlCE.

JOHN E. HILBISH1 OF LA GRANGE, ILLINOIS, ASSIGNOR- 'TlO K'ELLOGG SWITCHBOABID AND SUPPLY COMPANY, 01 CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

UNIVERSAL CORD CIRCUITS.

Application filed. January 30, 1919.

To all whom may concern:

' ll 3 it lmown that l, JOHN E. llrnsrsrr, icon of the llnited States of :imerica, re-

at La Grange, in the county of (look and i'ltatc of llliuois, have iuve ted certain new and usclul lmprovements in Universal (ford ircuits, of which the following is a specification.

My invention relates to telephone systems and has to do more particularly with systems or the universal type in which universai '-:0I('l circuits are provided for interconnecting telephone lines of dilllerent character :urch as magneto and common battery lines. The cord circuit ot my invention may be used to connect a magneto line to a mag:- ncto line; magneto line to a common but tery line; a common buttery line to a magneto line, and a common battery line to a common battery line.

[1 Feature of my invention is the provision ot a link circuit which may be used to es blish any of? the alivove-mentioned conhe ions and which cord circuit is provided with only sin' le wound relays thereby l'urnishinp; very etlicientvoice transmission.

The novel features of the invention through the provisions or? which the above-mentioned and other advantageous results are attained w ll he more fully explained with reference t the accompanying drawing in which preferred embodiment of my invention is shown To lhe left of the accou'ipauyiuo' d awing l show a calling common buttery substation A. term nating at the exchange in the line circuit l1. which comprises the usual line relay LR cut-oil relay t), answering iaclc and line signal A ma! ieto substation B is also shown terminating at the eschungre in a line circuit ll comprising the usual alror signal D9) and answering jack J. cord circuit C is provided which is adapted for interconnecting the different lines shown the said cord circuit (l being; used in olishiugg connections between common ha lery and local, battery lines; local hattery and common buttery lines; common battery and common battery lines and local battery and local battery lines.

The cord circuit C comprises an answering plug All? and a calling plus; GP, the said plugs being; connected. by the heavily marked conductors The conductors have repeating coil ll-(l interposed, the said coil RC comprising; windings 1 2, 3 and 4, and the Specification of Letters Patent.

Patented Aug. 22, 1922.

Serial No. 273,970.

mile 71 aid 2 are in suitable inductive "itiou with the coils 3 and 4. At the :werin end oi the cord circuit C, 1. prov vitchiug relay tllV which is connected to the third contact of the plug AP and l disconnect relay PR to become energized mon'ientarily t V o close a circuit tor the supervisory relay fillwhich in turn closes a circuit for the inswerinu supervisory lamp AL to give the (uiierator o? the cord circuit 1 a disconnect ll hcn the plug AP is connected to H 216k J ot a m gncto subscribers line the vip contact a o. 1e plug AP registers with :he tip spring a of the jack J, the ring; conact Z of the slug Al connects with the up; s nking, Z

V the plug J and the sleeve tact oi the plug AP registers with the sleeve c ol iacl ll. hen the plug AP of tin cord circuit is connect-ed to the jack r? of a common liuittciy subscribers line, the tip contact :4 oil the plug AP registers with the tip sprii (a ot the plug J, and the sleeve contact 1" ot the plug AP registers with the sleeve contact 0 of the jack J, the ring; contact- 7) ot the plug ill? not registerirp; with any contact of the jack J, but remuiniun' on open circuit. A ring-back key llll provided tor purposes which are well known in thc art and a listening: key LK is also provided which when actuated, connccts the operators set 0 to the cord conductors.

Tie calling: end of the cord circuit C is also provided with a switching relay SW, a disconnect relay DR and a supervisory relay f-lllr the said relays performing the same 'l'unctions as described in connection with the answering end of the cord C. A calling supervisory lamp CL is also provided for the usual supervisory purposes. The calling end oi the cord circuit C is also provided with a ringing; key RK which when actu- J and line signal S.

ated, connects the ringing generator (i to ring the call bell of a called-for substation. To the right of the drawing 1 show a com mon battery substation D terminating at the exchange in a line circuit L comprising the usual line relay LR, cut-off relay CO, ack

A magneto substation E is also shown teri'ninating; at the exchange in a line circuit If comprising; the usual. drop-signal DS' and jack Having described in general the apparatus as illustrated in the drawing; the operation of the system Will. now be described. in detail.

i lssun'iing that a. call is initiated at the common battery substation A, the subscriber at the substation in removing his receiver from the switch hook closed an energizing circuit for the line relay LR o'l": line circuit L over a circuit-traced from battery through i the Winding of relay lili normalcmitact r of relay CO through the closed contacts of the substation switch hook and back to around at normal contact 6 ol? relay Ct).

,The closing of alternate contact oil? relay LR causes the line signal S to clean and the operator noting the lighted signal, inserts the answering plug: AP of the cord circuit C into the jack J oi: the callingline. The insertion of the plug Al? into the jack l stablishes an energizing; circuit for the switching relay SW and the cut-off relay (7O traced From battery througljh the winding of relay S ob conductor 7, normal contact 8 of relay SW, conductor 9, sleeve contacts oil? the connected plug Al. and jack .l to ground through the winding: of: the cut off relay CO. The plug Al? is so constructed that when it inserted into the jack J oi a common batterv line, the ring; contact of the said plug AP slightly smaller than the sleeve of the jack, thus placing the riur: contact of plug: in. open circuit and allowing; the tip and sleeve contacts oi the respective plug anc jack Al and ,l to engage, thus utilizing a three-coeductor plug: as AP in connection with a. twoqvireline circuit as L. Upon the, energization of relay CO its contacts 5 and (S assume their alternate position HllOWiDii the line relay LR to restore to e'flace the line signal S. Upon the energization of relay (0, an. energizing circuit for supervisory relay SR is established. over a circuit traced from battery through the winding of rel ay fill, its alternate contact 10. conductor 1], winding; 2 of i ieating; coil RC1 condlurtor 19. makebet'ore-brealr contact 8" conductor 9 sleeve contacts of the plug AP and jack J tluroire'h the closed contacts ol the substation switch book, be rk .tlniousrh the tip contacts 01 the connected pluo AP and jack J. normal con tact 130i. the rimr-bacl: key RB. w nding: 1..

of the, coil RC, conductor .l -I-l. alternate con act 15 and conductor it; to ground through the winding of supervisory relay SE. The contacts 8 and 10 of the relay SW are so adjusted that the contact l0 closes when the relay liill is energized before normal con tact 8 is opened- The opening of normal contact 1.? ol relay SR prevents the premature lighting oi the answering supervisory lamp AL. The closii'uz; of alternate contact ll) of relay FilV closes a locking circuit for the relay SW over a circuit traced from loattery through the winding of: relay SW, its alternate contact 10, conductor 11, Winding 2 oil the induction coil RC conductor 12, alternate contact 8, conductm? 9, sleeve contracts of the plug A P. and aclt l to ground through the winding oi relay (h The said relay SW aiter once energizing remains energized until the plug AP is removed from the jack J. The operator now actuates her liar-nine key LK to connect her operatofis set i l to the cord conductors and inquires the wants oi the calling subscriber at substation A.

zlssumieur that it is the magneto substation ii that is \vautee, the operator inserts the calling: plug (/P into the jack J of the called. magneto line E. When plug; Cl is i. 1 l into jack J" no circuit is established 'lor the siviching relay Sil as the sleeve contact of the jack ii is not connected to anpaint!is therefore the switching relay W" remains at normal. The operator new achiates the ri sing: key BK to connect the 1.. 'enerator G to transmit ringing current to ring the hell of the called-for subscriber at substation the ringing circuit be ng traced from the ungrounded pole of l ,cencrato (i tillOllQfll alternate contact li ()l the key RK, t n contacts of the eomzectezl plug (1- and jack J through the call hell. at the substation E back through the ring; contacts ol the plug! and ack GP and J and conductor 19, to ground at alternate con act 520 of the key BK. The subscriber at the substation E n response to his call bell removes his receiver and the sul'iscrihers at substations A and E are now in eonversatimal circuit, the said talking circuit being. traced over the heavily marked conductors.

Assuming; that the subscribers have finished conversation, the restoration of the receiver at the substation A opens the circuit of the supcrvismry relay SR at the switchhook contacts and the closing of normal con tact 17 thereof establishes an energizing circuit for the answering supervisory lamp AL traced from battery through normal contact 17, conductor 21, alternate contact ,E replaces his receiver and aetuates his ing magneto line.

doctor 2;? winding 4- oil the coil contacts of the plug}; '1) and ack 4 other side of the generator at thsubstation The relay Dli is momentarily en ergiszed due to the impulse of current from the generator and the closure of alto .iate contact 28 or" relay DR closes a circn it for relay F ll traced from battery through alternate contact 28 of relay lI'lFL conductor 29, conductor 8% normal contact of relay SW. conductor 32 through the Winding of relay SE to ground. The closure oi alternate contact oi relay establishes a locking); circuit therefor, traced from ground, throng; the winding-ct relay SR, conductor 32, normal. contact ill, condnctor 30. normz'il contact i-ll ot the listening key Lilli, conductor normal contact 36 ot rel. r SW, and conductor 37 to hatt/er and ground at alternate contact of relay S tf The closing of alternate contact of relay SR also establishes an energizing circuit for tl e calling supervisory lamp oll b tl l -1t'-" iiom atteiy, nougi a elnate contact no, conductor 37, normal contact 2nd, conductor 35, normal contact 3 1- conductor 30, conductor 29, normal contact 28, and through the lamp CL to ground. The operator not- 1119; the trio lightedsuifervniory signals AL and (TL knows that conversation l terinin e il and now actuetcs her l nun; key Ll'l to open normal contact 334 which Now. it a call initia ed from in neto substation 13 the actuation oi: the hand generator thereat causes flow oi? current to pass 'tl'irough the *indin e' of the drop signal D9) of the line circuit L. A shutei of the drop signal BS is displayed to ttract her attention and the operator noting the actuated. drop signal, inserts the answering plug Al into the jack ll of t e callr The insertion of the plug AP in jack J restores the drop shu ter and also disconnects the winding of coil n 426 and thron 'h the drop signal DFl trom across the line. The SGll-l'lStOlllN drop l shown in Paten k lStln 1.902. The opera listening trey LK to c-t set 0 to the cord conducton i the Wants of the calling me.

get; .l being disconnected from ail paratus, no circuit is established for switching"; relay i ll i the said switching rcll V" therefore remaining at normal. The operator having ascertained the wants of the subscriber at magneto substation l3 4min that it the common in that is WllllJQCh the operator he calling glue; Cl? into the jack 3 ol the called common battery substation thus closing an rern'izing circuit for switching relay c ,J and the cut-oil rethe lay GS of: the line GLL'QU'il; L the circuit being; traced 'from l urttery through. the Winding o'i switching relay til i conductor ill, the malre-betore-breal contact a l, conductor 4-2, sleeve contacts of the connected plug C and ack J to ground through the winch ing of the out-oil relay 0G. The contacts 26 and 4'51. of relay Ell V are so adjusted that alternate contact 26 is closed to close a substitute circuit for relay SW" before normal contact all is openech and, of course, due to he make-before-brealz construction oi the springs all, after contact 26 is closed the alternate contact ll. is closed before nor: contact 41 is opened. The closing of alternate contact 26 of the switching" relay 5W establishes a locking circuit for itself traced from battery through the winding;

of the said relay Ell i its alternate contact 28., conductor 27} Winding 4 oil? the repeating l, condnchir 43, alternate contact 4-1 I, coiu'lnctor sleeve contacts of the connccted plu GP and lack (l and through amp {/l; traced from bat y hrongh nornal contact 33 of supervisory relay dill concuctor 4C5, alternate contact let, conductor a the lamp CL to ground. he lat-.np CL remains lighted until the d subscriber answers.

.tgcr new actuates the ringing to conl'icct the rij ring generator G he call bell of the subscriber at the D the said ring tom the nngroundgenerator G, through g; key BK. plug Cl? and l. and condense at the subs ion. D hacl: ough the contacts Olii' 'lille connected jacl; J and plug l and conductor 19 to ground at alternate 1 one.

ing curra on pole -:i alternate c tin contacts J thro connected 1 the "all l llG contact 20 of the ringing key RE. The subscriber at the substation D in response to his call signal removes his receiver from its re spective switch hool: to close the switchhook contacts. The closing oi the contacts thereat establishes an energizing. circuit for the su 'iervisory relay SR traced from ground through the winding of the said re lay SR, condiiictor 3 53, alternate contact of the r-uvitching relay SlV, conductor 24;, the wimling 3 oi the repeating coil RC, normal contac l8 oi the ringing key RK, tip contacts oi the connected plug CP and J through the now closed contacts at the substation switch hook oil? substation D, back through the sleeve contacts of the plug CP and jack J conductor 42, alternate contact eil, conductor 1:3, winding Al of the repeating coil RC, conductor 2? and alternate contact 26 of switching relay SW to battery and ground, through the winding of the switching relay SW. Upon the energizationot the supervisory relay SR, its normal contact 2-33 is opened which brings about the effacement of the calling supervisory lamp CL, notifying the operator that the called subscriber at the common battery substation D has answered. The talking circuit between the magneto substation l3 and the common battery substation D may be traced over the heavily marked conductors.

When conversation is completed, the calling subscriber at the magneto substation 15 places his receiver upon its switch hook, operates his hand generator, transmitting current from the hand generator through the ':ip contacts to the connected jack J and plug AP, normal contact 13,- winding 1 of the repeating coil RC, conductor 14, through the winding oil. the disconnect relay DR, conductor 50, normal contact 10 of the switching relay SW, conductor 11, winding 2 off the repeating coil RC, the ring contacts or. theconnected plug AP and jack J to the other side of the hand generator at the substation B. I The relay DR is momentarily energized by this flow of current and the closure of its alternate contact 51 establishes an energizing circuit for the supervisory nate contact 51, conductor 52, normal con-- tact 15 of the switching relay S /V, conductor 16 to ground, through the winding of the supervisory relay SR. The supervisory relay SR upon energization closes a locking circuit for itself traced from battery, through alternate contact 1701? the relay SR, conductor 53, normal contact 54- ot the relay SW, conductor 55, normal contact 56 of the listening hey LK, conductor 52, normal contact 15 0f relay SW, and conductor 16 to ground through. the winding or thesupervisory relay SR. A circuit for the answering supervisory lamp AL is also established upon the energization of relay SR,.traced of the cord circuit C that the subscriber at.

the substation B has signaled ior disconnect. The subscriber at the called commonv battery substation D upon replacing his receiver upon its said. switch hook opens the circuit tor the supervisory relay SR at the switch hook contacts, and. the closing of nor mal contact 33 of relay SR establishes an energizing circuit for the calling supervisory lamp CL, traced from battery, through nor-' mal. contact 33 of relay SR, conductor 45, alternate contact 4d otswitching relay SWV, conductor 46, and through the lamp CL to ground. The calling supervisory lamp CL is thus lighted and the operator noting the two lighted supervisory lamps AL and. CL knows that conversation has terminated, and actuates her listening key LK. The opening of normal contact 56 of relay LK opens the locking circuit "for the supervisory relay SR and also opens the circuit for the answering supervisory lamp AL, thus efl'acing the said lamp AL. The operator now withdraws the answering plug AP and the calling plug CP from their respective jacks J and J The withdrawal ot' the calling plug CP from jack J opens the energizing circuit for the switching relay SlV of thecord circuit C and the cut-off relay C0 of the line circuit L The relay SW7 upon deenergizing opens its alternate contact i l to eiface the calling supervisory signal CL. The apparatus used in establishing the above-described connection is now at normal and available for use in establishing other connections.

Should the magneto subscriber at the calling substation B wish to recall before the plugs have been Withdrawn, the continued actuation of the hand generator at the substation B transmits alternating current through the disconnect relay DR. This alternating current passing through the dis connect relay DR causes the said relay to chatter to open and close its alternate contact 51, thus producing a flickering eflect of the answering supervisory lamp AL. This distinctive flickering of the lamp AL notifies the operator that a recall is desired, distinguishing it from the steady glow of the answering supervisory lamp AL when a disconnect signal is given.

The operator in answering the recall actuates her listening key LK to open the normal contact 56, which restores the supervisory relay SR and efla'ces the supervisory lamp AL, and the operator having connected her cperators set 0 may now converse with the recalling subscriber. The recall of the c0mmon battery subscriber is caused by the subscribers switch hook being operated, causing the supervisory signal to flash, notifying the operator that the common battery subscriber wishes to recall. Should connection be established between the common batte y substations A and D the operation of the circuit can be readily fOllOWil rain the previous description, and likewise the connection between substations ano. E is readily apparent from the foregoing; description.

lVhile l have described. my invention in one specific form, I do not wish to be limited to the same, as changes and modifications will readily suggest themselves to those skilled in the art, and I. therefore, aim to cover also such changes and modifications as come within the spirit and scope of the appended claim What I claim as new and desire to secure by United States Letters Patent, is

A telephone system including a subscribers telephone line, a link circuit, a terminal for said link circuit for connecting said link circuit with said subscribers line, a relay connected to contact of said terminal and operable upon connection of said terminal to said line to connect itself to an cther contact of said terminal as well as to the first contact oi said terminal tl'irough contacts controlled by said relay, and a supervisory relay normally disconnected from said terminal, the connection of said supen visory relay with said terminal controlled by said first relay.

2. A telephone system including a sub scribers telephone line, a link circuit, a connection terminal for said link circuit "for connecting the same to said subscribers line. a relay for said link circuit connected through a normally closed contact or". said relay to a contact of said terminal, a circuit for said relay closed responsive to the con nection of said link circuit to said line, and contacts controlled by said relay for connecting itself to another contact of said terminal without disconnecting itself from said first contact, and a second relay normally disconnected from said terminal, the connection of said second relay and said terminal controlled by said first relay.

3. it. telephone system including a subscribei"s telephone line, link circuit, a connection terminal for said link circuit for connecting the same to said subscribers line, a supervisory signal, a relay for said link circuit connected to a contact of said terminal, a circuit for said relay closed responsive to the connection of said link circuit to said line, contacts controlled by said relay for connecting itself to another contact of said terminal, a second relay normally discon nected from said terminal, said second relay connected to a third contact oi said relay for connecting to be terminal and a source oi current adapted be bridged across said subscribens 1i throu 'h the windings or said relays.

to l ne 5. A. telephone sys i includi scrbers telephone line, a liuf:

ree-co'luluctor jGl'llli' cuit for connecting t sc ibers teleph. the third condr circui l link a same to line, a.

line. a second relay niniinal-l disconnected from said terminal, and contacts controlled by said lirst relay tor connectinn; itse c. d said second relay to the tel I conductors of said terminal whereby talking current is ted to the subscribers line. i

6. A. telephone system including; a subscribers telephone line, a link ci cui a three-conductor plug; for said link circuit iciconnectinig the same to said so scribers line, a tipervisory relay normally out of circuit \l'ltlz said plug, a switching relay connected to a contact of said plu and ope able when said link circuit is connected to said line to inlude said supervisory relay in circuit -.il1h said plug, and mea controlled by said switching r lay for connecting; itself to another contact of said plug: and for con-- necting together the said contacts of said plug.

7. A. telephone system iiutludiuna sub scribei"s telephone line, a link circuit for connection thereto, a supervisory signal for said link circuit, a relay for said link circuit responsive to current transmitted over said subscribers line by the subscriber at the substation thereon, a second relay responsive to the ()F J'BI'ZttlOl]. of said relay, a locking; circuit for said second relay indei jendent oi the said first relay and a. circuit for said r-super'visory signal maintained closed responsive to the de-enern ization of said first relay and the energg ization of said second. relay. and also maintained opened it said first re lay energized and said second relay is in its locked position to prevent the operation of. said supervisory device.

8. A telephone system including a subscribers telephone line, a link circuit for cult is connected to said subscr' j so co ction hereto, a supervisory signal for it. a relay for 1 link circuit adapted to be energised i onsive to cur rent tra sniitted over said subscri,be'="s line tation i iereon,

by the subscriber at the subs a second relay adapted to be energised responsive to the operation of said first relay,

locking circuitl'or said second relay independent of the said first relay and a circuit for said supervisory device clos cl 'esponsiye to the dcenergiaation of said first elay and the error ization of said second relay said sii 'iervisory device adapted to be intermit- Z operated by the imerniittent actuation fl first relay.

9 A telephone system including subscribers lines oi different cliaracter a linlr; circult prm'ided-witli plug; for interconnecting said subscribers lines, a pair oi? supervisory rela s normally disconnected from said plugs. a pair of switching relays for said linlr circuit normally connected to said plugs and YGSPORSlVG to the connection of said plugs and said subscribers lines to connect said su ervisory relays to said plugs, a pair ol relays normally bridged across the cononcors oi said link circuit and responsive to current iransmitted over the subscribers line to effect the operation of said supervisory rela' s, and a manuallycontrolled key 'lor controlling the circuits of said supervisory relays effected by the operation of d last pair of relays and the non-operation said switching relays.

10. A. telephone system including common attery and local battery subscribers teleihoue line-1 a linl; circuit provided with a ;air of plug; terminals for interconnecting said lines a pair of single-\ vound switching l ys for said link circuit a pair of superiy relays normally disconnected from d plug terminals, a pair of relays norially brai ed across the conductors o'fsaid iilli'l circuit, manually controlled key for controlling the circuits of said supervisory relays, and supervisory devices controlled by said relays.

Signed by me at Chicago, county of Cook and lltate of Illinois, this 28th day of Januairy .l9'l9.

J. F. HILBISH. 

